In recent years, sensors using the MEMS have been widely used for the purpose of image stabilization of a digital camera and attitude control of a vehicle or a robot.
Generally, this type of MEMS is formed by processing a semiconductor substrate such as a silicon substrate by using photolithography technology and etching technology, and it is provided with a semiconductor substrate, a movable body that is displaced in a predetermined direction and a plurality of beams joining the movable body and the semiconductor substrate. The MEMS is for detecting a physical quantity such as an angular velocity or an acceleration based on a displacement of the movable body.
Japanese patent No. 3669713 (Patent Document 1) describes an example of the angular velocity sensor. This angular velocity sensor is provided with oscillation generating means for oscillating an oscillator (movable body) around the oscillator and angular velocity detecting means for detecting an amount of displacement of the oscillator in a direction perpendicular to an oscillation direction as an angular velocity. At this time, the oscillator is fixed to a semiconductor substrate via a beam functioning as a spring, and this structure allows the oscillator to oscillate.
Japanese patent Application laid-open Publication No. 09-292409 (Patent Document 2) describes an example of the acceleration sensor. This acceleration sensor has a structure in which the movable body is fixed to the semiconductor substrate via a beam functioning as a spring in order to displace the movable body unidirectionally and the movable body is displaced in accordance with an applied acceleration. Also, acceleration detecting means for detecting an amount of displacement of the movable body as an acceleration is provided.
The angular velocity sensor in Patent Document 1 and the acceleration sensor in Patent Document 2 described above are called “sensor element”. That is, a semiconductor chip on which MEMS such as an angular velocity sensor and an acceleration sensor are formed is called “sensor element”. In an actual sensor, generally, the sensor element is mounted on a package body by using an adhesive agent, and it is necessary to connect the sensor element and an electrode formed in the package to each other via a wire so that a signal can be taken out of the electrode formed in the package.